Evaporative coolers (“swamp coolers”) are an extremely useful device for cooling in areas having low humidity. A fan blows ambient air across a wick, screen or other device for holding water on a large surface area. Evaporation of water cools the air flow substantially, without the heavy electrical requirements of an air conditioner compressor. The system obviously is tailored for low humidity parts of the country such as the mountain west, rather than for high humidity areas (where the degree of evaporation is constrained).
Residential evaporative coolers come in a number of standard types. In general, large roof mounted units have a down draft system in which a cool air supply duct exits the device from the bottom, passes through the roof of the domicile and then sends the cooled air into the home. Window units may be mounted on the window or may be mounted on the wall or ground beneath the window. A cool air supply duct exits one side of the system, passes through the window and then delivers the cool air to the home.
However, evaporative coolers have problems. First, the large area of screens or wicks inside the device can become dirty if left un-used for extended periods of time, such as a winter season. Second, since there is a water supply to the device and the cooler is necessarily mounted outside of the residence, during winter months the device must be kept warm or the water supply shut down. In addition, the large surface area of the unit (evaporative coolers are somewhat larger than air conditioners of equivalent capacity) may become dirty during long periods of disuse.
Thus, covering evaporative coolers during the “off season” is very important.
However, cooler covers known in the market suffer from a problem known as “cold crack”. “Cold crack” is a technical term referring to that temperature at which the cover itself cracks due to cold. Obviously, being mounted in a potentially humid location (the outside of an evaporative cooler) exacerbates this problem. Worse, “cold crack” becomes worse with age of the cover: a cover which survives a given low temperature during the course of one winter may “cold crack” the very next winter at the exact same temperature, simply due to aging of the cover.
In addition to age and cold crack characteristics, the ease of use of a cooler cover is important: working on a roof or near a window on a large and bulky cooler is difficult enough without additional effort imposed by badly designed cooler covers. In one common system on the market, a cover has a hook-and-loop fabric strip (such as VELCRO (r) brand hook-and-loop fabric) running along one or two edges. A user of the device must physically run their hands along the edges having the fabric on order to secure it inch by inch, which may require reaching portions of a cooler which are up against walls, just above roof tiles, or in other inconvenient positions. One rationale for this is that it allows easier use of the device on evaporative coolers of different shapes and sizes under the reasoning that it may not always be commercially feasible to provide a cover for a single model of evaporative cooler.
However, evaporative coolers tend to come in a small number of shapes (generally cubical and generally cylindrical), and even in fairly standard sizes. For example, a given development or neighborhood may have one or a small number of prevalent evaporative coolers. The “standardized” covers on the market might then be a nuisance for a number of home owners who all find themselves winter after winter trying to figure out the best way to stretch, wrinkle or fold the cover so as to provide a tight fit. Needless folding or stretching, of course, then contribute to aging and cold crack.
The US Patent and Trademark Office collection of granted patents reveals teaching on evaporative cooler covers.
U.S. Pat. No. 4,732,012 issued Mar. 22, 1988 for ENERGY EFFICIENT EVAPORATIVE COOLER COVER APPARATUS teaches a hard-sided assembly used to shade the device in summer or block the vents in winter. It does not teach any construction of solid flexible polymer layers nor a drawstring. It argues away from making an evaporative cooler exactly fit an evaporative cooler by teaching that the device should be larger than the evaporative cooler with an overhand all around.
U.S. Pat. No. 4,498,912 issued Feb. 12, 1985 for SUNSCREEN COVER APPARATUS FOR AN EVAPORATIVE COOLER teaches a flexible evaporative cooler device which actually does have triple layer construction, however, it teaches a body allowing air flow through the sides for summer use: the layers are screens, not solid polymers. It also fails to teach drawstrings and exact sizing to the evaporative cooler.
U.S. Pat. No. 4,101,609 issued Jul. 18, 1978 for COVER HOLDER FOR EVAPORATIVE COOLER teaches yet another rigid cover lacking drawstrings and exact size matching to a given model of evaporative cooler.
U.S. Pat. No. 3,938,694 issued Feb. 17, 1976 teaches yet another rigid cover device lacking drawstrings and flexible coverings for easy installation.
It would be advantageous to provide a flexible evaporative cooler cover having internal dimensions dimensioned and configured to equal the external dimensions of a single model of evaporative cooler.
It would be advantageous to provide a flexible, impermeable, evaporative cooler cover having superior cold crack characteristics.
It would further be advantageous to provide an evaporative cooler cover having superior aging characteristics.
It would further be advantageous to provide an evaporative cooler cover having convenient structures for fastening the device to the evaporative cooler.